For some purposes in the production of photographic images it is desirable to transfer hydrophilic colloid layers from a temporary support onto a permanent support to produce thereon the final image.
The transfer of a hydrophilic colloid layer or portions thereof from a temporary support to a permanent support is known e.g. in the production of decalcomanias, gravure resists, photostencils and wash-off processable photosensitive recording materials. Examples of the latter materials are described in U.S. Pat. Nos. 3,642,474 and 4,701,401.
Stripping films have been prepared on various temporary supports, e.g. on unsubbed cellulose triacetate sheet, a polyester sheet, a polystyrene sheet or a sheet of copoly(vinyl acetate/vinyl chloride) as described in U.S. Pat. No. 4,701,401.
Several measures have been proposed to improve adhesion in a dry state of a hydrophilic colloid layer on a polyester film support without however preventing the subsequent wet-stripping thereof.
Among the treatments to improve the dry-adherence of polyester film supports towards hydrophilic colloid layers that are recognized in the art are flame treatment described in U.S. Pat. No. 3,072,483 and electron bombardement and corona discharge treatment described in U.S. Pat. No. 3,220,842. However, these treatments often result in a too strong adhesion of hydrophilic colloid layers in a wet state to thus treated polyester supports. According to another technique the polyester support is first pre-coated with a sub-coating that is alkali-soluble so that a thereon coated silver halide emulsion can be peeled off easily after its treatment in alkaline developer solution and transferred to a permanent support, e.g. for the purpose of forming a decalcomania.